docs: def cleanup(self, force=False):
          """Clean up Yadis-related services in the session and return
          the most-recently-attempted service from the manager, if one
          exists.
  
          @param force: True if the manager should be deleted regardless
          of whether it's a manager for self.url.
  
          @return: current service endpoint object or None if there is
              no current service
          """
          manager = self.getManager(force=force)
          if manager is not None:
              service = manager.current()
              self.destroyManager(force=force)
          else:
              service = None
  
          return service